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Biomedical subjects

C T Su

Publications and source records attributed to C T Su.

At least 19 recordsLinked to original sources
PubMed1997

Case report: primary cystic keratinizing squamous cell carcinoma of the liver in a patient with treated nasopharyngeal carcinoma.

Primary squamous cell carcinoma of the liver is very rare; only 18 cases have been recorded. In the present report we document an additional case who had a unique history of stage III non-keratinizing nasopharyngeal carcinoma treated with a full course of radiotherapy in July 1993. Two small hypoechoic cyst-like lesions in the left hepatic lobe were identified at the same time. In July 1995 the 50-year-old patient reported to be suffering from abdominal fullness and tenderness. A large hypodense tumour was demonstrated in the left hepatic lobe by abdominal echography. The patient was diagnosed as having metastatic carcinoma and received two courses of pre-operative chemotherapy followed by left lobectomy of the liver and resection of adherent tissues on 9 August 1995. Pathological study demonstrated a larger hepatic cystic keratinizing squamous cell carcinoma, which most likely arose from a solitary hepatic cyst. Tumour seedings, probably secondary to tumour rupture, were also revealed on the omentum, peritoneum and diaphragm. However, regional lymph nodes were fee of tumour. Systemic work-up failed to demonstrate evidence of local recurrence of nasopharyngeal carcinoma, metastatic lesion or any second primary tumour site.

Antineoplastic Agents↗
PubMed1997

Postoperative MRI of anorectal malformation.

Twenty-five patients who had pull-through rectum (PTR) surgery, some of whom suffered from fecal incontinence, soiling or constipation were studied by magnetic resonance imaging (MRI) postoperatively. MRI demonstrated 14 patients with proper placement of the PTR between the puborectal muscle and external sphincter muscle; four patients with improper placement of the PTR outside the puborectal muscle and external sphincter muscle (one with excess perirectal fat); one patient with disruption of the puborectal muscle and external sphincter muscle; three with hypoplasia of the puborectal muscle and external sphincter muscle; three with asymmetric placement of PTR in the levator ani (one with excess perirectal fat). MRI also depicted seven patients with spine anomalies; five with tethered cord; and 10 with genitourinary tract anomalies. The patients with correct location of PTR all had good fecal continence except three patients (two with soiling and one with constipation) who had tethered cord and ganglion cell dysfunction at the PTR. The patients with improper placement of PTR or poorly developed pelvic muscles all had fecal incontinence. Our study emphasizes that MRI can depict the causes of postoperative incontinence, detect anomalies and help to plan further surgery.

Adolescent↗
PubMed1996

Evaluation of intracranial and extracranial carotid steno-occlusive diseases in Taiwan Chinese patients with MR angiography: preliminary experience.

BACKGROUND AND PURPOSE: We attempted to evaluate the location of vascular lesions in cases of cerebrovascular steno-occlusive diseases in Chinese persons living in Taiwan. METHODS: With three-dimensional time-of-flight magnetic resonance angiography (MRA) as a screening tool, 108 symptomatic patients with cerebrovascular steno-occlusive diseases were examined. Cardioembolic disease and cerebral hemorrhage cases were excluded. The degrees of stenosis of bilateral cervical carotid arteries and their major intracranial tributaries were recorded. They were categorized as nonsignificant stenosis (0% to 49%), significant stenosis (50% to 99%), and total occlusion. RESULTS: Our data revealed that 32.4% of the cases were normal in either cervical carotid arteries or their intracranial tributaries. In 24.1% of the cases, significant extracranial carotid stenosis or occlusion was the only finding on MRA. In 25.9% of the cases, only significant intracranial-tributary stenosis was found. In 17.6% of them, significant lesions were found in both extracranial and intracranial carotid artery tributaries. CONCLUSIONS: A racial difference between Chinese and white patients in location of lesion in cerebrovascular steno-occlusive diseases was confirmed. About one third of symptomatic Chinese patients living in Taiwan showed small-vessel disease. Approximately 24% of patients had only extracranial carotid disease, and about 26% had only intracranial carotid tributary disease. We need a larger series of patients to confirm these findings. However, MRA might be a good screening tool for steno-occlusive cerebrovascular disease, especially in persons of a race with more intracranial carotid disease, such as the Chinese.

Adult↗
PubMed1996

2-D time-of-flight (TOF) MRA of thrombophlebitis of upper extremity and subclavian veins. A case report.

In this report, the authors present a case of segmental thrombosis of left subclavian vein that was inaccessible to conventional venography and inconclusive in magnetic resonance techniques (spin echo, gradient echo) but was clearly demonstrated by two-dimensional time-of-flight magnetic resonance angiography (2D TOF MRA). This technique is very sensitive to detect slow flow or partial occlusion of the vessels and is of great help in solving the problem of axillary-subclavian venous obstruction or thrombophlebitis.

Adult↗
PubMed1996

Infectious spondylitis: MRI characteristics.

Magnetic resonance imaging (MRI) scans of 24 patients with clinically proven infectious spondylitis were retrospectively evaluated. Evaluation was made of abnormal signal and enhancement patterns within vertebral bodies, intervening disks, and epidural and paraspinal abscesses. The causative organisms included Mycobacterium tuberculosis, fungi and pyogenic bacteria. Staphylococcus aureus was the predominant causative organism among pyogentic bacteria. Decreased signal intensity of vertebral marrow on T1-weighted images was more extensive in pyogenic infections. Multilevel involvement (more than two) was observed in six of the 24 patients. Contiguous multilevel involvement was observed only in patients with tuberculous spondylitis. Noninvolvement of the intervertebral disk space was observed in two patients with pyogenic spondylitis. Epidural abscess was found in 15 patients, most of whom had dense, homogeneous enhancement. Paraspinal abscess was found in 18 patients. Diffuse patchy enhancement without obvious abscess formation in the paraspinal compartment was found in those patients with pyogenic infections. "Rice bodies" were found in paraspinal abscesses in only three patients with tuberculous spondylitis. It was difficult to differentiate candidal from tuberculous spondylitis on MRI. Compared with pyogenic infection, tuberculous spondylitis had a predilection for spinal deformity, subligamentous spread, contiguous multilevel involvement, presence of signal voids in paraspinal abscesses on T2WT and a lesser extent of marrow edema.

Adolescent↗
PubMed1996

Magnetic resonance imaging of vertebral compression fractures.

In this study, magnetic resonance imaging (MRI) was used to analyze the signal intensity and vascularity of compression fractures of vertebrae in 74 patients. The possibility of nonunion was assessed according to the specific image findings and clinical presentation. All patients had chronic back pain for more than 3 months and compression fractures of the vertebrae initially demonstrated by plain radiography. Pre-enhanced T1 and T2*-weighted images (*multiplaner gradient recall sequence) and postenhanced MRI were obtained. Images were divided into three categories according to the signal intensity of the fractured vertebrae such as hyperintensity (n = 35), hypointensity (n = 24) on T1-weighted image and necrotic type compression fractures of the vertebrae (n = 15). Of the 15 necrotic-type cases, 13 disclosed "fluid"-containing space at the collapsed vertebrae and two showed "air"-containing space at the vertebral body. We believe that these findings are pathognomonic signs of nonunion of the collapsed vertebrae. Surgical specimens were obtained from the four patients whose vertebrae showed necrosis and granulation tissue. After posterior spinal instrumentation, the collapsed vertebral body regained the height and presence of the open end-plate of the vertebra on postoperative lateral radiography. The superior capabilities of MRI offers useful criteria that make the diagnosis of nonunion in compression fractures of the spine possible. Thus, a space with "fluid" or "air" collection at the anterior aspect of a collapsed vertebra as well as strong enhancement with Gd-DTPA at the posterior aspect of the collapsed vertebra may be considered to be pathognomonic signs of nonunion of the fractured vertebra.

Aged↗
PubMed1996

Correlation between quantitative severity of stress thallium-201 myocardial perfusion defect and severity of coronary stenosis.

The correlation between the quantitative myocardial perfusion defect severity of stress 201Tl single-photon emission computed tomography and the severity of coronary stenosis was investigated in 28 patients with angina pectoris. Among the 28 patients, four had normal or nearly normal coronary angiograms, seven had one-vessel disease, six had two-vessel disease and 11 had three-vessel disease. Seven patients had prior myocardial infarctions and two had collateral flows to the diseased vessels. The quantitative 201Tl defect severity score was obtained by summing the standard deviations of each pixel in which the counts fell > 2.5 SD below the mean normal counts. The severity of coronary stenosis was expressed as the Gensini score. The quantitative 201Tl defect severity score correlated significantly with the Gensini score. In patients without prior myocardial infarction or collateral flow, a more significant correlation between the quantitative 201Tl defect severity score and the Gensini score was found. Quantitative analysis of stress 201Tl defect severity provides a useful, noninvasive assessment of the functional severity of coronary stenosis compared with coronary angiography.

Adult↗
PubMed1995

The depolarization response element in acetylcholine receptor genes is a dual-function E box.

All acetylcholine receptor subunit genes contain E boxes and are blocked by membrane depolarization. We have used transfected C2C12 myogenic cells to investigate the response, to electrical stimulation and KCl, of wildtype and mutant regulatory regions of the chick acetylcholine receptor alpha, gamma and delta subunit, and the mouse MLC genes. Point mutations revealed that E boxes function as activating elements targeted by the depolarization signal. These experiments suggest, and insertion of a depolarization response element into an unrelated promoter confirms, that plasma membrane depolarization switches the depolarization response element from an activating to a repressive mode.

Action Potentials↗
PubMed1995

Dynamic enhancement MRI of anterior lobe in pituitary dwarfism.

We examined 23 patients with pituitary dwarfism by dynamic MRI; with a repetition time of 150 or 50 ms. The time-enhancement difference curves of selected regions in the anterior lobes were plotted. Another 48 patients with no definite clinical pituitary disfunction were examined with the same technique. We found that the intensity of maximum enhancement in both groups was similar, but the time to achieve maximum enhancement was delayed in pituitary dwarfism with or without stalk transection; the time seemed longest with stalk transection. There was little difference in enhancement between patients with multiple hormone deficiency or isolated growth hormone deficiency. Dynamic MRI of the anterior lobes may be an important functional imaging study, and our results imply that poor perfusion is a useful finding in pituitary dwarfism, especially in patients without stalk transection and normal pituitary height.

Adolescent↗
PubMed1995

Dobutamine stress echocardiography compared with dipyridamole thallium-201 single-photon emission computed tomography in detecting coronary artery disease.

To compare the diagnostic value of dobutamine stress echocardiography with dipyridamole thallium-201 single-photon emission computed tomography (SPECT) in detecting coronary artery disease (CAD), we performed both tests on 54 patients who also underwent coronary arteriography. Dobutamine was infused at an incremental regimen of 5, 10, 20, 30 and 40 micrograms.kg-1.min-1. Dipyridamole was infused at a rate of 0.14 mg.kg-1.min-1 over 4 min. Dobutamine stress echocardiography detected 40 (93%) and SPECT 42 (98%, P = ns) of the 43 patients with significant CAD, defined as > or = 50% diameter stenosis. The specificity was 73% (8 of 11) for both tests. The sensitivity for detecting individual coronary artery stenosis with dobutamine stress echocardiography was 81% (30 of 37) for the left anterior descending artery, 75% (24 of 32) for the right coronary artery, and 61% (17 of 28) for the left circumflex artery. For SPECT it was 89%, 97% (P < 0.05 vs dobutamine stress echocardiography) and 75%, respectively. Among the 97 stenotic coronary arteries, 17 had mild to moderate stenosis (50%-69% diameter stenosis) and 80 had severe stenosis (> or = 70% diameter stenosis). With dobutamine stress echocardiography, 53% of the arteries with mild to moderate stenosis were identified vs 78% of those with severe stenosis (P < 0.05). With SPECT, the sensitivity was 82% (14 of 17) in mild to moderate stenosis and 89% (71 of 80) in severe stenosis (P = ns). No major side effects occurred during either test. Thus, both dobutamine stress and SPECT are highly sensitive for detection and localization of CAD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Changes of brainstem and perimesencephalic cistern: dynamic predictor of outcome in severe head injury.

OBJECTIVES: Based on the findings in computed tomography scans, we defined a grading system that is well correlated to the changes of the brainstem and its perimesencephalic cistern during intracranial hypertension. MATERIALS AND METHODS: The grades are defined as follows: Grade 0 is normal, grade 1 represents widening of the perimesencephalic cistern without brainstem change, grade 2 represents obliteration of the cistern without brainstem change, grade 3 represents a deformed brainstem; grade 4 represents brainstem density change, and grade 5 represents any combination of grades 3 and 4. As a comparison to the Glasgow Coma Scale (GCS) system, we examined this new system in 334 cases, in which 138 cases were classified as severe head injuries. RESULTS: In cases of mild head injury (GCS score > 8), this new system was correlated to the GCS system well in grades 0 to 2. In cases of severe head injury, the prediction of outcome is better in our system because it is well correlated to dynamic change of intracranial hypertension, especially in cases with nonsurgical masses of grades 3 and 5. CONCLUSIONS: Our grading system is easy to use, and is well correlated to give an accurate prediction of outcome in cases with severe head injury based primarily on the results of an initial computed tomography scan, even without clinical information, and it should play a role in the classification of head injury.

Adolescent↗
PubMed1995

MRI of meniscus and cruciate ligament tears correlated with arthroscopy.

Findings from magnetic resonance imaging (MRI) studies of 50 knees were retrospectively interpreted. The results were correlated with arthroscopic findings. Multiple pulse sequences were performed including sagittal double-echo, coronal T1-weighted and gradient echo, axial gradient echo or fat suppression imaging. Three-dimensional MRI was performed if there was a high suspicion of a tear of the anterior cruciate ligament. The individual positive predictive value, sensitivity, specificity and accuracy were calculated from the comparison between MRI and arthroscopic findings of the menisci, anterior cruciate ligament and posterior cruciate ligament. The following results were obtained: 1) Tears of the medial meniscus-positive predictive value, 72%; sensitivity, 87%; specificity, 86%; and accuracy, 86%. 2) Tears of the lateral meniscus-positive predictive value, 85%; sensitivity, 85%; specificity, 90%; and accuracy, 88%. 3) Tears of the anterior cruciate ligament-positive predictive value, 88%; sensitivity, 95%; specificity, 89%; and accuracy, 92%. 4) Tears of the posterior cruciate ligament-positive predictive value, 100%; sensitivity, 100%; specificity, 100%; and accuracy, 100%. It is concluded that MRI is a noninvasive and accurate method for detecting the internal derangement of the knee.

Adolescent↗
PubMed1994

Differential diagnosis of extrahepatic biliary atresia from neonatal hepatitis: a prospective study.

The clinical presentations of cholestasis in infancy caused by neonatal hepatitis and biliary atresia are very similar. Diagnosis may be difficult on many occasions, but the surgical treatment of biliary atresia should be performed as early as possible. We established a 3-day workup protocol for the differential diagnosis of biliary atresia and neonatal hepatitis and compared the diagnostic accuracy, sensitivity, specificity, and predictive values of various methods. One hundred and twenty-six infants, including 84 with neonatal hepatitis (age, 65.1 +/- 24.1 days) and 42 with biliary atresia (age, 60.3 +/- 31.1 days), were studied prospectively from July 1982 to December 1990. The diagnostic accuracy of various methods was as follows: liver histology, 96.8%; color of duodenal juice, 91.6%; peak radioisotope count in duodenal juice, 84.2%; ultrasonographic examination of the hepatobiliary system, 80.2%; and persistence of clay-colored stool, 80.2%. After stepwise logistic regression, the diagnostic methods of significance were liver biopsy, color of duodenal juice, abdominal ultrasonography, and stool color. However, stool color and the onset of jaundice could not differentiate severe neonatal hepatitis from biliary atresia. The diagnostic methods of significance then were liver biopsy and duodenal juice color. With this 3-day protocol, no biliary atresia was missed although four cases of neonatal hepatitis were misdiagnosed, resulting in unnecessary laparotomy; we found an overall diagnostic accuracy of 96.8%. We conclude that this 3-day diagnostic protocol is very helpful in the differential diagnosis of neonatal hepatitis and biliary atresia. Liver histologic examination is the most reliable single test for the differential diagnosis.

Biliary Atresia↗
PubMed1994

Findings of anomalous pulmonary venous return using MRI.

This study represents a preliminary retrospective assessment of the value of spin-echo magnetic resonance imaging (MRI) in detecting and describing total or partial anomalous pulmonary venous return (APVR). MRI was performed in 21 cases of APVR; orthogonal planes were used in all. Of the 21 cases, 19 were classified as total APVR (TAPVR) and two were partial APVR (PAPVR). Of the 19 cases of TAPVR, seven supracardiac, nine cardiac, one infracardiac and two mixed type were noted. The detection rate of each pulmonary vein combined in all three planes was 57% in the right superior pulmonary vein (RSPV), 62% in the left superior pulmonary vein (LSPV), 76% in the right inferior pulmonary vein (RIPV), and 86% in the left inferior pulmonary vein (LIPV). The axial plane was most effective (RSPV: 38%; LSPV: 52%; RIPV: 71%; LIPV: 81%). The coronal plane offered a better detection rate than the axial plane in RSPV (43%) and additional information of bronchial and visceral situs. Imaging of the combined axial and coronal planes was sufficient to evaluate each individual pulmonary vein. The sagittal plane gave no additional information in this respect. Accurate identification of pulmonary venous confluence and anomalous pulmonary venous channel was 95% (20/21). Limitation of echocardiography and and angiocardiography makes cardiac MRI important in assessing pulmonary vein and pulmonary venous confluence. It obviates the need for invasive angiocardiography and is an important supplement to an inadequate echo.

Adolescent↗
PubMed1994

Magnetic resonance imaging of rotator cuff lesions.

The purpose of this study was to evaluate the diagnostic performance of magnetic resonance imaging (MRI) in rotator cuff diseases. Forty consecutive patients studied by MRI from September 1990 to September 1992 were included in the study. MRI was performed on a 1.5 tesla MR scanner. Each MRI study was reviewed by two radiologists experienced in rotator cuff tendons. The MRI finding was compared with the surgical result. MRI sensitivity for all tears (partial and complete) was 1.0 (22/22), specificity 0.89 (16/18), accuracy rate 0.95 (38/40), and the predictive value 0.92 (22/24). Signal changes of the rotator cuff tendon (primary signs) were the most reliable criteria in diagnosis of the tear. Changes of subacromial and subdeltoid fat planes and bursa (secondary signs) were complimentary when primary signs were indeterminant. The direction of the long axis of abnormal signal intensity in the rotator cuff tendon may be a good indicator when differentiating tears from tendinitis. We conclude that MRI shows excellent performance in the determination of the presence or absence of a rotator cuff tear.

Adolescent↗
PubMed1993

Evaluation of hip disorders by radiography, radionuclide scanning and magnetic resonance imaging.

Thirty-six hips were studied because of significant hip pain. Radiography of the hip and bone scintigraphy showed subtle changes. Magnetic resonance imaging (MRI) was performed using a 1.5 Tesla superconductive unit. All MRI findings were confirmed by surgical or pathologic results. Twenty-nine hips had a single lesion, including: infection (one), fracture (eight), avascular necrosis of the femur(two), or contralateral hip (four), transient osteoporosis (six), osteoporosis (one), post-irradiation myositis (one), metastasis (four), and synovitis (two). Twenty-six lesions (89.6%) appeared normal on the radiographs of the hip, while three lesions (10.4%) showed only osteoporotic change. Another seven hips had more than one lesion, including: avascular necrosis and fracture (four), fracture foci (two), and metastasis and fracture (two). Radiography of the hip showed either a negative finding or detected only a single lesion, missing other important pathologic foci. MRI is extremely sensitive to alterations in the bone marrow that may represent pathology occult to plain radiography and bone scintigraphy of the hips. For diagnosis and treatment planning, MRI of the hips should be performed early in patients with persistent pain and negative radiography findings.

Acetabulum↗